PROBLEM TO BE SOLVED: To provide a hydrocarbon composition which has a reduced amount of impurities content other than a target component as compared with the existing hydrocarbon composition, is excellent in storage stability, slippage at the time of application (smoothness), gloss after application, stability under light irradiation, lubricity, and mold releasability, and has a reduced environmental load, and to provide a production method thereof.SOLUTION: The invention provides a method for producing a pasty composition which comprises performing decarboxylation dimerization reaction against fatty acid composition in which (1) the content of a branched chain fatty acid is 70 mass% or more, (2) the content of a branched chain fatty acid which is liquid at 25°C and has one carboxylic acid is 65 mass% or less, and (3) the content ratio of a branched chain fatty acid which is liquid at 25°C and has two or three carboxylic acids to the branched chain fatty acid is 10 mass% or more, and subsequently performing hydrodeoxygenation reaction against the obtained aliphatic ketone.【課題】既存の炭化水素組成物と比較して、目的とする成分以外の共雑物含有量が低減され、保存安定性、塗布時の滑性（滑らかさ）、塗布後の艶、光照射下における安定性、潤滑性、及び離形性に優れ、環境負荷を低減した炭化水素組成物とその製造方法の提供。【解決手段】脂肪酸組成が、（１）分岐鎖脂肪酸の含有量が７０質量％以上であり、（２）１個のカルボン酸を有する２５℃で液状の分岐鎖脂肪酸の含有量が６５質量％以下であり、かつ（３）分岐鎖脂肪酸に対する、２又は３個のカルボン酸を有する２５℃で液状の分岐鎖脂肪酸の含有割合が１０質量％以上である、脂肪酸組成物に対して、脱炭酸的二量化反応を行った後、得られた脂肪族ケトンに対して水素化脱酸素反応を行うことを特徴とする、ペースト状組成物の製造方法。【選択図】なし
